The Compact All-in-One AMI MUSIK DDH-1 Audio Music Interface

The AMI MUSIK DDH-1 ($549)
These days, many of us use computers as transport. No more fiddling with optical media—just call up a big list of albums in your media player software of choice. It's great to be presented with multiple terabytes worth of music, to be combed through by artist or genre or year, or just browse by album cover. It brings the simplicity of an iPod type experience to the home, with a much larger display and without any sonic compromise.

I mention compromise because there's usually something. For those with massive budgets and unlimited space, it's not hard to find DAC and amp separates that do the job well. Maybe even add in a preamp for your speaker rig—why not? You've got no shortage of cash or room. For others though, it's not always so easy. Many folks use their desktop as a sort of catch all music space—the headphone listening takes place there, and throw some active monitors in the mix as well. Most desktop situations don't allow unlimited space for big separates, so we enter the realm of the all in one DAC/amp/preamp unit.

There seems to be no shortage of these types lately. Some of them are really quite good too. But if you're really strapped for space, many of these are just too bulky, and lot of them start at $1,000 and go up from there. Size can be a factor, and you'd be surprised at how many of these leave out some important features. Under review today is one that doesn't lack much at all—the AMI Musik DDH-1.

Design and Features
Hailing from Tokyo Japan, AMI (short for Audio. Music. Interface. Seriously, that's how they write it with the periods) is an up and coming firm with a lot of new models on the drawing board. The DDH-1 ($549) is their first release—a compact, full featured unit with more functionality than you can shake a stick at, including some you maybe didn't even know you needed. This thing is seriously small at 4.5 inches wide, under 6 inches deep, and less than 2 inches in height, and should fit into even the most crowded desktop environment. Allow me to break down the features since there's a lot to cover.

First up is the DAC section. The DDH-1 is centered around the 32-bit Texas Instruments PCM1795 DAC. It features an XMOS-based asynchronous USB input capable of handling 24-bit/192kHz data. Interestingly, AMI chose to use a newer USB 3.0 type B port. It's not a true USB 3.0 input, mind you, but AMI figured they would physically accommodate the newer style cables as those will become more and more common. Of course, it still works with USB 2.0 cables if that's what you have, it's just not quite as robust of a connection. Also worth noting is compatibility with the iPad via the Camera Connection Kit which is not something you find in a lot of 24/192 capable devices. Toslink and coaxial SPDIF ports, which I suppose by now are considered "legacy" formats, are on board as well.

What's that I see? A 1/8" analog input? Surely that's just used in a pinch to feed music from a cell phone or something, right? True, that input does route sound to the line out or headphone amp sections, but there's more to it than that. It actually runs the signal through an AKM AK5386 analog to digital converter, which results in a 24-bit/96kHz digital signal accessible through the Toslink output. So this little device could be used to digitize analog recordings from whatever source you might have. Ever want to mess with needle drops of your favorite vinyl albums? The DDH-1 can do that. Or maybe you have a collection of cassette tapes from local bands which will never in a million years be released on any other format. The DDH-1 can archive those too, and from my testing it does a great job of it. This function does require a sound card with an optical input capable of accepting 96kHz signals, which most decent soundcards can do by now (though integrated sound solutions in motherboards seem to have moved on to HDMI). It would be nice to have the option of capturing incoming analog signals directly through USB, but I can only think of one similar device (Alpha Design Labs GT40) that works that way.

Let's see... what else to mention? The Toslink output will pass through information from the USB input, meaning the device can act as a dedicated (and rather high quality) USB to SPDIF converter. A rear panel switch sets the output to either fixed or variable, so those not using the volume control for preamp duties can get that unnecessary stuff out of the signal path—though in my experience it seems pretty transparent. Up front, AMI had the foresight to add headphone jacks in both 1/4" and 1/8" varieties. I suppose it's no big deal to slap on an adapter, but somehow it just feels "right" to use a dedicated jack in the proper size. As if that wasn't enough, the unit has dedicated sample rate indicators to help keep track of incoming signals. I really can't think of another all-in-one cramming anywhere near this much into such a small box.

I have to say I like the attitude displayed by AMI—they come right out and list the specific components used in the DDH-1. Go HERE and scroll down a bit, then choose "components" and you'll see exactly what the guts of the device are made of. This means I spend less time describing all this stuff in my review, but more importantly it shows a certain confidence in their choices—like they have nothing to hide. Noteworthy items, aside from those previously mentioned, include the TI DIX9211 (a new and very high quality digital audio receiver), a TPA 6120A2 headphone driver, low jitter TCXO system clock, and Nichicon Fine Gold capacitors. Power supply is a larger external unit much like you'd find with a small laptop computer. AMI uses a DC to DC converter to generate the supply voltage, so this is a more complex solution than the simple wall-wart as commonly found in this size/price segment.

AMI uses quad opamps to form the analog output stage: a National LM49860 stereo opamp handles I/V conversion, and another of the same chip handles low-pass filtering. Then dual NJM2114D bipolar opamps are used as a buffer, feeding the line out as well as the headphone driver. All opamps are socketed to encourage swapping—though the stock opamps are of rather high quality, AMI wanted to allow for experimentation or to achieve different flavors of sound. I tried a few different opamps I had lying around and found myself going right back to the originals for the best balance and overall character. But I'm glad the option is there, and maybe one day I'll find something that does offer a substantial improvement.

AMI International, Inc.
Level 9, Ariake Frontier Building Tower B
3-7-26 Ariake
Koto-ku, Tokyo 135-0063, Japan

XVII's picture

Till it would be great if you found new Desk Of Fame with categories like:

Portable DAC

Portable AMP

Portable DAC/AMP

Desktop DAC

Desktop AMP

Desktop DAC/AMP

So we could follow your recommendations easier without digging through Other Product Reviews))


By the way if it possible could you please rewiew some realy inexpensive DAC like this NuForce uDac-3.

John Grandberg's picture

It's something I've considered but never quite hashed it out with Tyll yet. Need to get on that I guess. 

Not sure about your definition of "inexpensive" but I do plan on covering the $350 Resonessence Labs Herus DAC/amp. 

Tyll Hertsens's picture

I wanted to get some time under our belts reviewing stuff here, but I think we're probably at the point where we can begin to develop WoF categories for amps, DACs, and portable boomboxes. We'll take it up soon.

Merck's picture

A Wall of Fame for other audio products would be nice.  I just ask that you don't go the same route has gone.  Their Top Picks section pretty much consists of the majority of products they review.  One only has to scroll through a few pages of articles to see that they are adding new items to the list almost every other review.I have a hard time trusting that section anymore after seeing very poor choices being made.  I haven't yet lost faith in this site though.

John Grandberg's picture

Most of the stuff us contributors review will get a "Stuff We Like!" rating. Tyll only has so much room/budget for submissions, so it makes sense to use it highlighting good stuff. Once in a while something is interesting enough or high profile enough to deserve a writeup, even though we don't end up recommending it. Most of the time the coverage of "bad" stuff will come from Tyll himself (he has a gift). 

The Wall of Fame is reserved for the best of the best. So among a bunch of stuff we might try, only the good ones deserve reviews, and only the best of those make the WoF. I hope that makes sense. 

Three Toes of Fury's picture

@XVII: your timing is perfect!   between Tylls recent reports from headphone/amp conventions and postings like his article today,  i was planning on requesting an Amp Wall-o-Fame.   You not only did that,  but provided some great categories!

Tyll:  if you do end up doing an Amp wall-o-fame,  please set it up like you've done for headphones...namely offering a nice price range (low to high) of offerings per category. 

Peace .n. Living in Stereo


PS:   whats the street date for the Ultimate headphone guide?  I cant wait to pick it up!!

John Grandberg's picture

...will keep it ordered by segments. No use lumping a $200 amp with a $2,000 one. 

Last I heard, the Ultimate Headphone Guide is printing now and should be ready to buy some time this month. Not sure exactly when though. I have a hunch Tyll will post about it when it happens. 

Tyll Hertsens's picture

Plan on posting about it Monday. I believe the guide should be on newsstands now. Just trying to get word about where folks might look, but it seems it's not quite as simple as one would think. The guide goes into distribution and then it's sort of lost relative to where it will actually show up. 

I've got some paper copies now though, and am totally stoked this will be out there.

paul's picture

Good review and thank you for not plugging in the HD800's.

The ATH-M50's and its brothers could use a shake-out at this price point.

jherbert's picture

I do not quite understand why anybody would care for a highend Headaphone Amp based on the TPA 6120A2. While it is easy to implement its output impedance of 10 ohms means its a nogo for anybody using inears or phones with an impedance of less than 70 ohms.

I also have a hard time believing there are audible differences between the various implentations of this chip. 

John Grandberg's picture

I doubt the target market for this device would buy it with the assumption they are getting a true "high-end" amp as part of the deal. It's good, but not amazing. At $550 for amp, DAC, preamp, and DDC, I don't even see how that's possible. 

That said, the TPA6120A2 certainly has potential. The specs are excellent. I recall amp guru Kevin Gilmore referring to this chip as sounding "mighty good indeed", and felt it was superior to opamps/buffers (the context there was portable amps but a compact all in one desktop unit isn't so different). He liked it more with higher impedance cans and I mostly feel the same way.